1. Field of the Invention
The present invention relates to a device and communications system for transmitting and receiving data via optical communications with another device, said device being provided on a laptop computer, digital camera and the like.
2. Description of the Related Art
Data transmission and reception among a plurality of personal computers, or between a personal computer and various peripheral devices is conventionally achieved through a cable. Infrared transmission reception(communications) systems using optical communications also are well known as data communication systems not requiring a cable. In such systems, infrared transmission units comprising an LED and sensor are mutually opposed on both devices, so as to transmit data via optical signals between the two devices. IrDA (Infrared Data Association) standards have been proposed as an infrared interface for data communications.
In conventional laptop computers and digital cameras and the like, a single infrared transmission reception unit is provided at the back or side of the device body. The effective light transmission reception angle of the infrared transmission reception unit is about 15 degrees. Accordingly, when conducting infrared communications between two laptop computers, the disposition of the two computers is restricted.
For example, when performing data communications between two laptop computers 100 provided with an infrared transmission reception unit 102 on the right edge of cover 101 which accommodates a built in liquid crystal display unit, as shown in FIGS. 5a and 5b, the infrared transmission reception units 102 of both computers 100 are placed facing one another such that both computers 100 are facing mutually opposite directions. For this reason it is difficult for one person to operate both computers 100 to effect the data transmission reception operation.
FIG. 6 shows a transmission reception method for transmitting data between laptop computers 100 provided with infrared transmission reception units 102 on the back. In this instance also the computers 100 are disposed so as to face mutually opposite directions so as to make it difficult for a single person to perform the transmission reception operation on the two computers 100.
An object of the present invention is to eliminate the previously mentioned disadvantages.
Another object of the present invention is to increase the freedom of disposition of each device when transmitting receiving data via optical communications with another device.
Another object of the present invention is to improve the operating characteristics of each device when transmitting receiving data via optical communications with another device.
Yet another object of the present invention is to provide a device capable of easy data transmission reception via optical communications with another device.
These and other objects are attained by providing a device having an optical communications function comprising a plurality of communications units for optical communications with other devices, wherein each communication unit includes a detection means for detecting whether or not another device is transmitting, and a communications means for performing communications using the communications unit which detected a transmission from another device.
The aforesaid objects of the present invention are attained by a device provided with a body, a plurality of transmission reception units provided on different surfaces of the body for optical communications with other devices, a data conversion unit comprising an encoder for encoding information for transmission from the transmission reception unit to another device and a decoder for decoding encoded information received from another device, a selection means for selecting one transmission reception unit for handling data with the data conversion unit from among a plurality of transmission reception units, a switching means for controlling the selection means so as to sequentially switch the transmission reception units to handle information and the data conversion unit, a detection means for detecting whether or not another device is transmitting, and a communication means for stopping the switching means when transmission from another device is detected and executing optical communications using the selected transmission reception units.